GMAC Mortgage LLC, the mortgage servicer that vaulted “robo-signing” into the headlines, says it has overhauled its foreclosure procedures.

The unit of Ally Financial Inc. has put each employee who works on foreclosures through an additional 40 hours of training, testing them on what they learned. Outside law firms that handle foreclosures for GMAC must answer questions about their own practices and are subject to on-site reviews.

The changes came after GMAC employee Jeffrey Stephan said in a deposition last year that he had signed off on as many as 10,000 foreclosure documents without proper review.